Sewing machine



March 4, l52

Filed Feb. 10, 1949 C. W. MUELLER SEWING MACHINE 3 Sheets-Sheet lINVENTOR CHARLES w. MUELLER BY :6? y-M ATTORNEY March 4, 1952 w, MUELLER2,588,274

SEWING MACHINE Filed Feb. 10, 1949 3 Sheets-Sheet 2 INVENTOR CHARLES W.MUELLER ATTORN EY March 4, 1952 c. w. MUELLER 2,588,274

SEWING MACHINE Filed Feb. 10, 1949 3 Sheets-Sheet 3 INVENTOR CHARLES W.MUELLER age/7M ATTORNEY Patented Mar. 4, 1952 SEWING MACHINE Charles W.Mueller, St. Louis, M0,, assignor to Lewis Invisible Stitch MachineCompany, a

corporation of Maine Application February 10, 1949, Serial No. 75,619

Claims.

The invention herein disclosed relates to a sewing machine of the kindin which'a looper receives a loop of thread formed on the return strokeof the needle, twists the loop and presents the loop for passagetherethrough by the needle on the next or penetrating stroke of theneedle. More particularly, the invention relates to a mechanism fordriving or actuating the looper.

As constructed heretofore and prior to this invention, the drivemechanism for the looper, particularly in blind-stitch, chain stitchsewing machines has been in a large measure, a limiting factor on thespeed at which the machine can be operated. A relatively complicatedso-called knuckle or looper joint has been used, and due to itsconstruction there is no way of providing a continuous supply of oil tothe relatively movable parts thereof in bearing or surface contact.

An object of this invention is to provide, in a machine of the kindmentioned, a comparatively simple drive mechanism for a looper. Anotherobject of the invention is to provide a looper joint to which oil may becontinuously supplied. A further object of the invention is to provide alooper joint that may be operated at comparatively high speed.

The foregoing objects and certain advantages that will hereinafterappear are realized in the embodiment of the invention illustrated inthe accompanying drawings and described in detail below, from whichdescription a clear understanding of the invention may be had.

The drawings include:

Fig. 1 which is a front elevation of a machine embodying the invention;

Fig. 2 which is a fragmentary, end elevation of the same showing thelooper drive mechanism, taken on the line 2--2 of Fig. 1;

Fig. 3 which is a fragmentary transverse section taken on the line 33 ofFig. 2;

Fig. 4 which is a fragmentary, sectional elevation of the same taken onthe line 4- of Fig. 2 and showing the crank rotated through one hundredand eighty degrees;

Fig. 5 which is a fragmentary end elevation similar to Fig. 2 with thecrank rotated clockwise through ninety degrees,

Fig. 6 which is a similar view with the crank rotated one hundred andeighty degrees from the position shown in Fig. 2;

Fig. '7 which is a like view with the crank rotated two hundred andseventy degrees from the position shown in Fig. 2;

Fig. 8 which is a fragmentary, sectional view taken on the line 8-8 ofFig. 2;

Fig. 9 which is a transverse section taken on the line .9-9 of Fig. 4;

Fig. 10 which is a side elevation of a bushing showing the oil groovetherein;

Fig. 11 which is a view similar to Fig. 4 showing a modified arrangementof an oil cup; and

Fig. 12 which is a sectional elevation of the oil cup of Fig. 11, takenon the line l2|2 of Fig. 10..

The particular sewing machine illustrated in the drawing, for thepurpose of disclosing the invention and in which the looper drivemechanism of the invention is especially desirable, is a blindstitch,chain-stitch sewing machine. This machine includes a frame upon andwithin which all of the mechanism is mounted. The frame comprises a baseI, a post or standard 2 secured to the base at the rear thereof, an arm31 extending laterally from the upper end of the post, aforwardlyextending arm 4, secured to the end of the arm 3, and a work table 5secured to the base at the front end thereof and extending to theforwardly extending arm 4. The several sections of the frame are hollow,and within and on the sections, operating and driving mechanism aremounted.

The sewing machine is actuated through a main shaft 6 that is journaledin the post 2 and the arm 3. This shaft extends through the post and hasfixedly mounted thereon a combined pulley I and hand wheel 8. The pulleyis driven by a belt 9 from a power shaft or an electric motor, notshown.

On the end of the arm 4, there is a presser foot [0 that overhangs theend of the work table 5. The work, the cloth being sewn, is supportedagainst this presser foot. The presser foot is of the usual andwell-known construction and has an opening therethrough, through which,during the operation of the machine, successive nodes of the materialbein sewn are projected.

The stitch-forming mechanism is of the usual and well known kind insewing machines of this type. A needle bar shaft I2 is journaled in thearm 4 and extends through the forward end thereof, the end near theoperator. On the extended end of the arm I2, there is secured a needlebar l3 which carries a curved needle l4. Through suitable connectionswith the main shaft 6, the needle the needle and the cloth as the needlereturns. The looper moves into this loop, engages the loop, withdraws,turns to twist the loop, and returns to position the loop so that on thenext succeeding penetrating stroke of the needle, the needle passesthrough the loop after passing through the cloth. The looper then shedsthat loop and returns to pick up the next loop thrown on the returnstroke of the needle.

The invention herein disclosed provides a novel and improved mechanismfor actuating the looper. One specific embodimentof the looper drivingor actuating mechanism is illustrated in Figs. 2 to 11 of the drawings,This particular mechanism is actuated by the main shaft 6 of the sewingmachine.

The end of the main shaft 6 is provided with a reduced end portion 6a.On this reduced end portion 6a, there is mounted a crank 16. The crankI6 is a counter-weighted or balanced crank, and it is provided with acrank arm I! that is inclined to a plane radial to the axis of the shaft6. The crank arm ll is provided with an opening I8 therethrough.Abushing I9 (Figs. 4 and 10) has a reduced end portion 20 which extendsthrough and makes a forced fit in the opening of the crank-arm ll. Theenlarged end 2| of the bushing extends beyond the crank-arm. The bushingl9 forms a bearing for a crank-stud 22 that extends therethrough and isjournaled therein.

The crank-stud 22 is provided with a head 23 that engages the extended,free end of the portion 29 of the bushing l9. This crank-stud extendswell beyond the bushing it. It is hollow and has an elongated slot 2?;formed through one surface adjacent the free end thereof, and two oilholes 26 and 21 drilled through the wall intermediate the ends thereof.It is held in the bearing bushing 19, against longitudinal movement withrespect thereto, by a block-J8 that is clamped thereon and extendslaterally therefrom. The block 28 abuts against the end of the largersection 2| of the bushing H).

The block 28 carries a pivot pin 29 which extends through an openingtherethrough and is fixedly secured therein by a set screw 39. The pivotpin opening through the block, and the pivot pin 29 are spaced from andextend at right angles to the axis of the crank-stud 22. A fiat surface3! is provided on one side of the pivot pin, against which the end ofthe set screw 39 abuts to secure the pivot pin in a fixed position withrespect to the block 23. Diametrically opposite the slot 3|, there isprovided, in the pivot pin 29, an oil groove 32 which extendslongitudinally of the pivot pin. l.

The pivot pin 29, that is the extended ends of the pivot pin 29,receives and constitutes a pivot for the bifurcated end 33 of a yoke 34.The bifurcated end 33 of the yoke 34 embraces the block 28, and the armsthereof are provided with bearings 35 and 36 which are journaled on theextended ends of the pivot pin 29. The yoke 34 has an internallythreaded, split end 37 which receives a complementary threaded end of alooper carrier or looper bar 33.

The looper bar 38, adjacent the free end thereof, has secured thereon apartial, spherical fixture or member 39. This partial, spherical sector39 is received in a complementary opening in an arm 40. The arm 49 isfixed to a stud 4! by a clamping screw 42. The stud 4! is journaled inan eccentric 42, which in turn is journaled in a bracket 43 extendingfrom and integral with the arm 4. The eccentric 42 is provided with aknurled finger wheel 4 by means of which it may be manually rotated inthe. bracket 43 so as to adjust the position of the looper H5. Thelooper bar or carrier 38 is provided, at its free end, the end extendingthrough the arm 49, with an offset portion 45. To this offset portion 45of the looper carrier, the looper i5 is secured.

The looper joint, consisting of the crank-stud 22, bushing l9, crankblock 28, pivot pin 29 and the arms 35 and 36 of the yoke 33 arelubricated by a sight oil cup 45. In the embodiment of the inventionshown in Figs. 2 to 10, the oil cup 46 is mounted on the rear wall 4'!of the arm 4. An oil delivery tube 48 connecting with the bottom of theoil cup 46 extends through the wall, the rear wall 41 of the arm 4, to apoint over the slot 25 in the crank-stud 22. "With this arrangement, asis well known in the art, a drop of oil is released from the end of thetube 43 at definite, timed intervals. In the construction illustrated, adrop of oil released from the tube 45 will fall into the slot 25 in thecrank-stud 22. Notwithstanding the rotation of the crank with the shaft6, the slot 25 in the crank-stud 22 will always remain beneath the endof the fixed oil tube 48.

As seen in Figs. 2, 4 and 5 to '7, regardless of the position of theshaft 6 or crank arm H, the slot 25 of the crank-stud 22 remains underthe end of the oil tube 48 leading from the oil cup 16. The crank-stud22 does not rotate about its axis. In view of its inclination (Fig. 4),it forms with the prolongation of the axis of the shaft 6, a trianglewhich on rotation of the shaft 6 generates a cone' The slot 25 of thecrank stud 22, at the intersection of the prolongation of the axis ofthe .shaft 6, never changes its position with respect to the end of theoil line or tube 48. Thus, regardless of the position of the shaft 6 orthe crank arm [1, the slot 25 of the crank-stud 22 is always in positionto receive oil dropping from the end of the stationary oil line 48. Thefree end of the crank-stud 22 is closed by an internally, force-fit cap49 so that no oil can flow from the free end of the crank-stud.Regardless of the position in which the crank-stud receives oil throughthe slot 25 therein, it retains that oil, and in its elevated orupwardly inclined position, such as illustrated in Figs. 2 and '7, theoil received through the slot 25 flows to the oil openings 26 and 21.

The bushing 19 and the block 28 are provided with oil holes and oilgrooves to distribute the oil received in the crank-stud 22 to thebearing.

surface of the bushing l9, and the oil groove 32 in the pivot pin 29.

For this purpose, the oil hole 26 through the wall of the crank-stud 22is located at the free edge of the portion 2! of the bushing 19. Theinternal surface of the bushing I9 is provided with an oil groove 50 ofthe kind that is commonly termed in the art, a Fig. 0 oil groove. Theoil groove 50, in the bushing 19, is open through the end of the section2|. Thus, oil passing through the oil hole 26 in the wall of thecrankstud 22 can enter the oil groove 59 to provide oil between theinternal surface of the bushing l9 and the crank-stud 22 and alsobetween the end surface of the bushing 19 and the block 28.

The oil hole 21 (Figs. 8 and 9) through the wall of the crank-stud 22 isaligned with an oil hole 5| in the block 28 which extends from theopening therethrough, through which the crank-stud 22 extends, to theopening through which the pivot pin 29 extends. The opening 5| isaligned with the oil groove 32 in the pivot 29. Thus, through theseopenings and the groove 32 both bearings 35 and 36 of the yoke 34 arelubricated by oil dropped into the slot 25 of the crankstud '22.

A modified arrangement for applying oil to the slot 25 in the crank-stud22 is illustrated in Figs. 11 and 12 of the drawings. In thisarrangement, an oil cup 52 is mounted below the arm 4 and directly abovethe slot 25 in the crank-stud 22. An oil tube 53 extending verticallyfrom the oil cup 52 is directly over the slot 25 in the crankstud 22 atthe position where the slot 25 intersects a prolongation of the axis ofthe shaft 5. The upper end 54 of the oil cup projects slightly throughthe frame of the arm 4 so that it is readily available for filling thecup with oil. The oil cup 52 is provided with a manually adjustablearrangement for regulating the amount of oil supplied to the crank-stud22. For this purpose, the bottom 55 of the oil cup is provided with aconicar seat 56 through the apex of which an oil supply hole 5! extends.The fiow of oil through the oil hole 51 is regulated by a ball 58 whichis positioned to engage the conical seat 56. The ball 58 is supported ona block 59, within a depending skirt 50 on the bottom of the oil cup,which block is in turn supported on the end of the hollow rod or tube53. This hollow rod or tube has a conical end 6| engaging acomplementary seat in the block 59 and openings 62 through the side wallthereof. The tube 53 has a portion 63 with an external thread thereon inthreaded engagement with an internal thread on the skirt 60. 'Thus, byrotating the tube 53, the ball 58 may be moved toward or away from theseat 56, and the flow of oil through the tube may be regulated. Forrotating the tube 53, there is provided a finger lever 64 which extendsoutwardly beyond the edge of the arm 4.

From the foregoing description of the embodiment of the inventionillustrated in the drawing and described in detail above, it will beseen by those skilled in the art that by this invention there isprovided a drive mechanism for actuating a looper that may be run atvery high speed, that is simple in construction, and that is soconstructed that oil may be continuously supplied to all parts inbearing contact.

It will be obvious that various changes may be made by those skilled inthe art in the details of the embodiment of the invention illustrated inthe drawing and described above within the principle and scope of theinvention as expressed in the appended claims.

I claim:

1. In a sewing machine of the kind described having a looper-carrier,drive mechanism for the looper-carrier comprising in combination a 1'0-tatably mounted drive shaft, means for rotating the shaft, a cranksecured on the end of the shaft, a crank-stud rotatably mounted in thecrank, extending therefrom and inclined to the axis of the drive shaft,a. member secured to said crank stud and extending laterally therefrom,and means pivotally connecting said looper-carrier to said member on apivot having an axis spaced from and at right angles to the axis of saidcrank stud.

2. In a sewing machine of the kind described having a looper-carrier,drive mechanism for the looper-carrier comprising in combination arotatably mounted drive shaft, means for rotating the shaft, a cranksecured on the end of the shaft, a crank-stud rotatably mounted in thecrank, extending therefrom and inclined to the axis of the drive shaft,a member secured to said crank stud and extending laterally therefrom,and means pivotally connecting said looper-carrier to said member on apivot having an axis spaced from and at right angles to the axis of saidcrank stud, the several parts having oil passages for supplying oil tothe surfaces thereof in rubbing contact.

3. In a sewing machine of the kind described having a looper-carrier,drive mechanism for the looper-carrier comprising in combination arotatably mounted drive shaft, means for rotating the shaft, a cranksecured on the end of the shaft, a crank stud rotatably mounted in thecrank, extending therefrom and inclined to the axis of the shaft, ablock secured to the crank stud and extending laterally therefrom, apivot pin carried by the block, spaced from the crank stud and extendingat right angles to the crank stud, and a member connected to saidloopercarrier and pivotally mounted on said pivot pin.

4. In a sewing machine of the kind described having a looper-carrier,drive mechanism for the looper-carrier comprising in combination arotatably mounted drive shaft, means for rotating the shaft, a cranksecured on the end of the shaft, a hollow crank stud rotatably mountedin the crank extending therefrom and inclined to the shaft, the crankstud including a portion having a slot therein extending across theprolongation of the axis of the shaft, a block secured to the crank studintermediate the ends thereof and extending laterally of the axisthereof, a pivot pin secured in the block, spaced from the axis of saidcrank stud and extending at right angles thereto, a yoke embracing theblock and pivoted on said pivot pin and connected to said loopercarrier,the said crank stud, block and pivot pin having oil passagestherethrough, and an oil feed mounted above the slot in the crank studand positioned to drop oil into the slot.

5. In a sewing machine of the kind described having a looper-carrier,drive mechanism for the looper-carrier comprising in combination arotatably mounted drive shaft, means for r0- tating the shaft, a cranksecured on the end of the shaft, a hollow crank stud rotatably mountedin the crank, extending therefrom and inclined to the axis of the shaft,the crank stud including a portion intersecting the prolongation of theaxis of the shaft and having a slot through the wall thereof and oilpassages through the wall between said slot and the crank, a blocksecured to the crank stud intermediate the ends thereof and having apivot pin opening therethrough spaced from the crank stud and extendingat right angles thereto and an oil passage connecting one of the oilpassages through the wall of the stud and the pivot pin opening, a pivotpin fixed in the opening in the block and having an oil groove in thesurface thereof communicating with the oil passage in the block, a yokepivoted on said pivot pin and connected to said looper-carrier and meansfor delivering oil to the slot in the crank stud.

CHARLES W. MUELLER.

Name Date Kelso Apr. 2, 1940 Number

